Printing frame



H. C. JONES PRINTING FRAME March 31, 1936.

Filed Dec. 5, 1933 3 Sheets-Sheet l IN ENTOR Harry fines.

ORNEY March 31, 1936.

H. C. -TIQNES PRINTING FRAME Filed Dec. 5, 1933 5 Sheets-Sheet 2 I hav INVENTOR Ham 6' 15/765.

ATT RNEY H. C. JONES PRINTING FRAME March 31, 1936.

Filed Dec. 5, 1953 5 Sheets-Sheet 5 INVENTOR Harry C J nes.

Patented Mar. 31, 1936 UNITED STATES PATENT OFFICE 18 Claims.

This invention relates to apparatus for printing alight sensitive surface through a sheet of transparent material, and particularly, to photographic contact printing apparatus.

,, My invention is adapted for application to a wide variety of contact printing apparatus, regardless of how contact between the negative and the sensitized surface is attained, and contemplates the provision of eflicient and comparatively 10 low cost printing means.

My invention further contemplates the provision of lever means for manipulating the movable parts of printing means which require more than a trifling amount of power to effect the 15 desired movement.

My invention further contemplates the provision of economical means for supporting the flexible material or blanket of the printing means to prevent side motion of the blanket when the 20. two holding frames usually employed in contact printing are put together.

My invention further contemplates the provision of contact printing means employing a pair of interchangeable holding frames, and of means for so supporting and manipulating the frames as to interchange their relation quickly, easily, economically and efficiently.

My invention further contemplates the provision of cushioning means for preventing shocks 30 and jarring when the holding frames are manipulated.

The various objects of my invention will be clear from the description which follows and from the drawings, in which,

35 Fig. 1 is a side elevation of my new apparatus.

Fig. 2 is a front elevation thereof.

Fig. 3 is a side elevation on an enlarged scale of the left end of the frame manipulating lever showing the means for supporting and connecting the upper ends of the holding frame operating cables.

Fig. 4 is a top plan of my new apparatus.

Fig. 5 is a vertical section of the same, taken on the line 55 of Fig. 2.

= Fig. 6 is a cross section of the manipulating lever taken on the line 6-6 of Fig. 2.

Fig. 'I is a fragmentary vertical section taken on the line 7-1 of Fig. 8 of the blanket-carrying holding frame.

50 Fig. 8 is a plan view of the same, the blanket being shown partly broken away to expose the blanket supporting structure.

Fig. 9 is a section taken on line 9-9 of Fig. 10 and similar to Fig. 7, of a modified form of the blanket supporting means,

Fig. 10 is a plan view of the same similar to Fig. 8.

Fig. 11 is a. fragmentary vertical section of the means for locking the lower holding frame, taken on the line ll|l of Fig. 1. 5

Fig. 12 is a side elevation similar to Fig. l of a modified form of my new apparatus.

Fig. 13 is a front elevation of the same.

Fig. 14 is a similar fragmentary view of a modified form of the lever operating means. 10 Fig. 15 is a similar view of another modified form of the same.

Fig. 16 is a front elevation of one of the chain sprocket wheels of Fig. 13 showing the chain secured thereto. 15

In that practical embodiment of my invention which I have shown by way of example, my new apparatus comprises generally, a pair of interchangeable holding frames and means for easily manipulating whichever frame is arranged upper- 20 most.

Said frames are usually movable relatively to each other to permit the insertion of the negative and. of the sensitized surface on or into one or the other of the frames. One of the frames is adapted to carry a blanket and the other frame is adapted usually to carry a glass. Where contact between the negative and the sensitized surface is produced by vacuum, the frames are provided with means for sealing the frames together and particularly, for sealing the space between the glass and the blanket and thereby permitting the blanket when under vacuum suction, to force the sensitized surface into intimate contact with the negative which is backed by the glass. 5

Since for different types of work, vacuum printing frames are sometimes used with the glass uppermost and the blanket below the glass, and at other times with the glass below the blanket, means are provided for manipulating that frame 0 which happens to be uppermost, and for interchanging the frames to reverse the positions thereof when desired. I have also provided means for so holding the blanket as not to detract materially from the flexibility thereof while at the same time supporting the blanket in such a manner that any danger of the blanket causing relative movement of the negative and the sensitized surface is prevented. The frames above described being of such large size that they are quite heavy, they cannot be directly manipulated manually, but require manipulating and supporting means so that the frames may be brought together and separated when desired.

With the above in mind, the description of the particular means which I have illustrated for carrying out the various aims of my invention may proceed.

Referring to Figs. 1 and 2 particularly, a pair of frames 20 and 2| are separately supported. I will refer to said frames hereinafter as the holding frames to distinguish the holding frames from the entire apparatus which is commonly known as a printing frame. The lower frame 29 may be either a blanket holding frame or a glass holding frame, the upper frame 2| holding the glass if the lower frame is the blanket holder, or holding the blanket if the lower frame is the glass holder. In any case, the lower frame is pivotally supported upon the standards 22 as by means of the brackets 23, each located at one of the ends of the lower frame and each pivoted to the adjacent standard by a suitable pin 23.

The flange 25 of the bracket 23 is of sufficient height to extend substantially as far above the upper surface of the lower holding frame as it extends below said surface. Said flange is removably secured to the lower holding frame in any suitable manner as by means of the bolts or screws 26. A suitable bracket as 2?, removably secured to the standard 22 is provided with a stop 28, (Figs. 1, 2, 11), adapted to engage the under surface of the lower holding frame to maintain said frame in the horizontal position into which it is swung about the pins 24. The pin 29 on said bracket 21 is adapted to removably engage an end of the lower holding frame to lock said frame in its horizontal position when desired, said pin being removable to permit swinging of the frame into upright position, in which position the lower holding frame engages the removable stop 38 arranged on the foot of the standard 22.

The upper holding frame 2i is supported in horizontal position by means of a pair of frame supports 3!, each of which is adjustably carried by a slide 32. The frame support is provided with a pair of arms 33 diverging upwardly and each terminating in a semi-cylindrical recess 34.

A pin 35 projecting from the end of the frame is inserted into each of the recesses 34 whereby the upper holding frame is supported by the frame support until said frame support is withdrawn from the pins 35.

As will be later explained in more detail, it sometimes becomes advisable to adjust the frame support relatively to the slide 32. I therefore prefer to connect said support to the slide by wing screws as 33 cooperating. with a selected one of the series of holes 37 in the slide 32. Said slide is mounted for longitudinal movement upwardly and downwardly on the standard 22 when the upper holdingframe is to be moved in the corresponding direction.

It will be understood that the slide moves downwardly past the pivot pins 24 of the lower holding frame. when it is desired to secure said frames together. Toward this end, the slide 32 embraces the standard 22 on three sides, being held in place by suitable narrow gibs 38 (Fig. 4) engaging the fourth side of the standards. It will be understood that where the standards are round instead of'square in cross-section, the slide 32 is of corresponding shape and suitably embraces the standard 22 for slidable movement thereon in a manner which will be obvious and hence which need not be described nor illustrated.

In order to interchange the positions of the lower and upper holding frames, the manipulatingmechanism later to' be described is operated to lower the upper holding frame 2! upon the lower holding frame 28 into the position indicated by the dash-dot lines of Fig. 1. It will be understood that the frame 25 is provided with pins 33 corresponding to the pins 35 in the upper frame but reversed in position. That is, the left pin 39 of the lower frame is arranged at the same distance to the left of the center of the standard 22 as is the right hand pin 35 of the upper frame; similarly, with the right hand pin 39 of the lower frame and the left hand pin 35 of the upper frame.

After the upper frame has been lowered as above described, onto the lower holding frame, the slide 32 is lowered as far as it will go on the standard 22, whereby the frame support 3| is removed from the pins 35 of the upper holding frame. In order, however, to provide sufficient clearance to permit the swinging of the holding frame, it is advisable to lower the frame support still further. This is done by removing the wing screw 35 holding the support to the slide, where-- by the support may be lowered relatively tothe slide and the wing nut re-engaged with the lower hole. The holding frames may now be interchanged. This is done by removing a set of the bolts or screws 26 which enter the lower holding frame 20 and inserting said bolts or screws through the openings 39 of the bracket flange 25 and into the upper holding frame, leaving one set of bolts in the lower holding frame until the upper frame has been properly secured at both ends to the flange 25. The remaining bolts 26 may now be removed from the lower frame and inserted into the proper openings 43 of the upper frame.

The upper frame being thus secured to the bracket 23, and the lower frame being thus freed,

from said bracket, the locking pin 29 is removed as are the stops 28 and 3B. The frame support 3| having been dropped. sufiiciently below the pins 33, the holding frames may now be swung as a unit about the pivot pins 24 to arrange the upper holding frame lowermost and the lower holding frame uppermost relatively to each other. It will be understood that the pins 39 of the lower frame now assume the position formerly occupied by the pins 35 of the upper frame whereby the supporting arms 33 may be raised on upward movement of the slide so that said pins 39 enter the recesses 34 of the arms and the looking pin 29 and the stops 28 and 3!! replaced.

7 On the upward movement of the slide 32, the holding frame, which is now uppermost, can be raised, leaving the holding frame which is now lowermost in the position formerly occupied by the lower frame 29. It will'be understood that the interchanging of the frames above described can be accomplished Without the necessity for removing the frames from the apparatus and at a minimum expenditure of time and labor.

The means for manipulating the slides 32 may take a variety of forms, some of which will now be described. As shown, said means comprises the rocking arm or lever 41 preferably H-shaped in cross-section (Fig. 6) which is pivotally supported by the fulcrum pin 42 on the bracket 43, said pin being arranged nearer one end of the arm than the other. Said bracket is mounted on a suitable cross member 4a secured to and bracing the standards 22.

The slides 32 are connected by suitable cables to the cable pin 45 carried by the bracket 33 arranged on and projecting overthe end of the rocking arm. A pair of such cables 47 and 48 are provided, the upper ends of said cables being connected to the cable pin 45 and the other end of each of the respective cables being connected to one of the slides 32 as at a suitable pin 45 secured to the slide. The cable 4! passes about a pair of revoluble cable sheaves 50 and 5! and as has been indicated, is secured at its upper end to the cable pin 45. From the pin 49, the cable 48 first passes about the cable sheave 52 (Fig. 2) and then about the sheaves 53 and 54 and is similarly connected and secured at its upper end to the pin 45. It will be understood that the sheaves 55 and 53 are of the same diameter and are coaxially aligned (Fig. l) and that the sheaves 5| and 54 are similarly of the same diameter and coaxially mounted.

A suitable bracket 55 secured to one of the standards 22 is employed to revolubly support the sheaves 50, 5|, 53 and 54.

It will be seen that as the cable pin 45 is raised or lowered on the manipulation of the rocking lever M, the upper ends of both cables 41 and 58 are raised or lowered precisely the same amount, and consequently raise or lower both slides 32 the same amount, whereby the holding frame carried by said slides is also raised and lowered the same amount at both ends thereof. It will further be understood that the weight of the upper holding frame and of the slides is transmitted through said cables to the cable pin and consequently, to the rocking lever, whereby when the rocking lever is swung in a counterclockwise direction, the cables 41 and 48 are slackened and the frame 2| drops on the standards 22 by gravity though means for positively lowering the frame may be employed if desired, as Will be obvious to those skilled in the art.

In order to overbalance said Weight and to maintain the upper holding frame in the position into which it is moved by the m anipulation of said rocking arm or lever, a counter weight 56 is slidably mounted on the rocking arm. To said counter weight is secured the safety stop 51 bent about the lower edge of the rocking arm and adapted to prevent vibration or displacement of the counter weight on the rocking arm. At its right end, the arm is provided with a suitable stop 58 of rubber or other suitable material adapted to engage the weight to limit the movement thereof toward the right, a similar stop 59 being arranged near the other end of said rocking arm to limit the movement of the counter weight toward the left. Depending flanges on the weight arranged within the flanges of the H-shaped rocking arm serve to prevent side movement of the weight on said arm. At its right end, the counter weight is provided with a suitable projection 6l to which is secured one end of the weight operating cable 62.

Said cable passes over the sheave 53 revolubly mounted at the right end of the lever as by means of the bracket 64, and terminates in a Weight or handle grip 1|. Another section of the cable 62 similarly terminating in a hand grip "H passes upwardly about a second upper sheave 6! (Fig. 4) in coaxial alignment with the upper sheave B3 and extends toward the left along the length of the rocking lever to the sheave 68 at the left end of the lever, said cable then passing back to and being connected to the left end of the counter weight as at 69.- The sheave 68 is revolubly supported by a suitable bracket as 70 arranged near the left end of the rocking lever.

It Will be seen that as one side or the other of the cable 62 below the sheave 63 is pulled downwardly by the: cperato'r',. the counter weight 56 is moved along the rocking arm in the desired direction. If the cable is manipulated to move the counter weight toward the left from the position shown in Fig. 2, as said counter weight approaches the fulcrum pin 42, the weight of the upper holding frame and the parts connected thereto is balanced less and less, so that the rocking arm begins to drop under the unbalanced weight of the arm and the frame, thereby lowering the upper holding frame. As the counter weight moves past the fulcrum pin 42, the movement becomes more rapid.

In the dotted line position of the rocking arm shown in Fig. 2, the counter weight rests against the left stop 59, the upper holding frame has been lowered to rest on the lower holding frame and the slides 32 have been lowered along the standards 22 to the dotted line position of Fig.

1, wherein the supporting member 3| has been removed from the pins of the upper holding frame. It will be understood that when the cable 62 is operated in the opposite direction, the counter weight is drawn toward the right end of the lever until it engages the stop 58, thereby raising the slides 32 with comparatively little effort on the part of the operator.

Means are preferably provided for cushioning the last part of the rocking movement of the rocking arm in either direction. said. means preferably takes the form of a pair of pneumatic steps 12 and 13 of any well known type and which therefore need not be described in detail. It need merely be said that the left stop 72 is adapted to engage an arm as 14 projecting from the bracket 70 to cushion the lowermost part of the downward movement of the left end of the rocking arm. Similarly, the pneumatic stop 13 is adapted to engage the arm 15 projecting from the rocking arm, on the last part of the downward movement of the right end of the rocking arm. Said stops 72 and 13 serve also to aid in overcoming the inertia of the rocking arm, the stop 12 aiding in the clockwise or frame raising movement and the stop 13 aiding in the frame lowering or counter-clockwise movement.

It will be understood that the fulcrum pin 42 is so arranged that when the counter weight is at the extreme right end of the rocking arm and adjacent the stop 58, considerable leverage is obtained, said leverage being sufficient to maintain the upper holding frame in its raised position.

As has been previously indicated, it is advisable to have the holding frames 2!! and 21 interchangeable so that the blanket-holding frame may be arranged uppermost if desired. It therefore becomes advisable to provide a blanket which though flexible, is not likely to sag and which is so supported as to prevent side motion thereof when the holding frames are brought together, without danger of the negative or sensitized plates being moved from their correct positions. It will be understood that such movement would interfere with correct registry.

Referring to Figs. '7 and 8, I have there shown a comparatively rigid sheet 8!) of composition board or thelike supported in one of the frames as the frame 20, by means of a series of bent sheet springs 8!, suitably secured on the four inner sides of the holding frame at spaced intervals and secured to the sheet 80.

Secured to the upper face of the sheet 83 but not to theblanket in the position shown in Fig. '7 are a pair of. spaced sections 82 and 83 of a As illustrated,

'weight passes the fulcrum moving toward the narrow strip of suitable durable and strong material. To form the space 84 between said sections, the intermediate section as 85 of the strip is secured to the under face of the blanket 86, but not to the sheet as. A plurality of strips are thus secured at spaced points of the area of the sheet 86 and thereby serve as a securing means for holding selected spaced points of the blanketv to the comparatively rigid sheet 80. The flexibility of the blanket is preserved by the yielda'ble springs 85 and the yieldability of the strips but undue movement of the blanket is prevented, since the blanket is compelled to carry the sheet 8!] with it during its movement on the application of vacuum to the holding frames, and complete flexibility of the blanket is nevertheless retained, permitting it to fit all the irregularities of the sensitized plate and to make intimate contact at all points. Should the frame 20 be reversed in position so that the blanket 86 is uppermost instead of lowermost, then the blanket in its attempted movement attempts to carry with it the comparatively rigid sheet 8i? whereby its movement is restricted sufficiently to prevent the dangers above mentioned.

In the form of my invention shown in Figs. 9 and 10, an open network 87 of intersecting wires is held to the frame 20 as by means of the springs 88 each secured at one end to the network and at the other end to the angle member 89, which is in turn attached to the inner face of the frame. It will be understood that one of such springs is preferably provided for each end of each of the wires. To secure the network to the blanket 85, a series of suitable strips 96 are provided, said strips being secured and held in place by the wires of the network and being also secured to the under face of the blanket. It will be understood that the blanket is thus supported either in its uppermost position or in its lowermost position in the frame against undue movement which might affect proper registry of the negative or of the sensitized plate or both.

In use, the upper holding frame 2! being in its raised position as shown in Figs. 1 and 2, the sensitized plate is laid on the blanket 85 and the negative is then placed correctly on said sensitized surface. By now operating the cable 62, the counterweight 56 on the rocking arm M is moved toward the fulcrum 42. When said stop 59, the upper holding frame 2| begins to drop by its own weight until it comes to rest on the lower holding frame iii. The rocking arm 4! at the same time swings in a counter-clockwise direction, the last part of its movement being resisted by'the engagement of the arm 14 with the stop 12. During this movement of the rocking arm or lever, the cables 4'! and 48 are relaxed whereby the weight of the frame acting through the supports 3! causes the slides 32 to move downwardly along the standards 22.

After the holding frames are brought together as above described, the vacuum may be applied at the connection 9| (Fig. 2) to draw the blanket and the sensitized plate and negative carried thereby together into intimate contact. The blanket 86, however, while flexible, is sufficiently restricted in its movement to eliminate any danger of relative movement of the negative and the sensitized surface. It will be understood that my invention is not necessarily limited to vacuum printing frames nor to printing frames only, but that contact between the sensitized surface and the-negative may be effected by any of the methods'customary in the art, and that my invention may also be applied to the movement of the negative frames of photo composing machines bythe proper arrangement of the lever, cables and negative frame.

After contact has been produced, the safety catches 92 on one of the holding frames are engaged with the pins 93 on the other holding frame to fasten the frames temporarily together. The thus locked frames may be swung into printing position on the removal of the locking pin 29, it being understood that the supporting member 3! has been dropped down into substantially the dotted line position of Fig. 1 to become disengaged from the pins 39 of the lower frame when the rocking arm :3! has been swung into the dotted line position of Fig. 2. The frames may now be swung about the pivot pins 24 into substantiallyvertical position wherein the lower holding frame engages the stop 30 and the printing operation may proceed in the usual manner. After the printing is completed, the holding frames are.

swung back to horizontal position, the lower frame being re-engaged with the stop 23 and the pin 29 re-inserted. By operation of the cable 62 in the proper direction, the counterweight is now drawn toward the right along the rocking arm, and as.

it passes the fulcrum 42, the combined action of the counterweight and of the stop 72 begins to swing the rocking arm in a clockwise direction, thereby to raise the upper holding frame. The sensitized surface and the negative carried by the lower frame may now be removed.

Should the blanket be arranged on the upper frame instead of on the lower frame, it will be understood that the blanket is sufficiently supported by the supporting means shown in Figs. '7 to 10 inclusive to prevent displacement of the sensitized surface relatively to the negative positioned on the glass on the lower holding frame.

Referring now to that form of my invention shown in Figs. 12 and 13, I have there shown a modified form of the means for operating the rocking arm Al.

Said means takes the form of a standard chain block M36 comprising the chain it! and a pair of suitable chain-engaging sprocket wheels as: and H13 secured respectively to the left end I6 3 of the rocking arm and to a suitable hook 5535 at the lower part of the standard 22. The left end we of the rocking arm carries a chain Sill. Said chain llll passes about the sprocket wheel i539, which is keyed to the shaft 5 iii, said shaft being carried by a suitable bracket l l I on the standard 22. A freely mounted chain guard H2 serves to maintain the chain I E3? in place about the sprocket wheel IE9. Said chain is carried upwardly and secured to the sprocket wheel H3 mounted on a suitable bracket carried by the member id.

Secured to the shaft i Ill for rotation therewith are a pair ofsprocket wheels l is, l 55 of the same diameter and of greater diameter than the wheel I89. One chain H6 is. secured to the sprocket wheel H4 and passes downwardly about the sprocket wheel Ill freely mounted on the stud shaft H8, which shaft is in turn suitably sup-.

ported as by the bracket H3 at the foot of the standard 22. The chain I5 is then brought upwardly from the sprocket wheel ill to the pin 529 on the slide 32 to which the end of the chain is secured. V v

A second chain i2l is similarly secured at one end to the sprocket wheel H5 (Figs. 13 and 16) passing thence towards the right about the loosely mounted sprocket wheel I22 to be secured to the pin I23 onthe right'slide 32 It will be seen that rotation of the shaft H and consequent rotation of the sprocket Wheels H4, H on said shaft moves the chains H6 and I2I precisely the same distance, in the same direction and consequently moves the slides 32 upwardly or downwardly the same amount to cause uniform movement at both ends of the upper holding frame 2 I.

Such rotation of the shaft IIB and of the sprocket wheels thereon is efiected by suitable operation of the chain IIII of the chain block I00 to raise or lower the right end I04 of the rocking arm and thereby to lower or raise the left end I06 thereof and to release or tighten the chain I01. It will be understood that the distance through which the left end I06 of the rocking arm moves is less than the distance which the upper holding frame 2| moves during the same time, this being due to the difierence in diameters of the sprocket wheels I09 and H4, H5.

The sprocket wheel II 3, therefore, is made of sufficient diameter to take about its circumference, a length of the chain lIl'I equal to the greatest distance through which said left end IIlS of the rocking arm may move. A torsion spring I24 acting between the collar I25, on the shaft I26 on which said sprocket wheel I I3 is mounted, and the hub of said sprocket wheel provides a spring take-up for the chain I t! to maintain said chain taut at all times.

By means of the reduction sprocket wheels I08, I I 4, I :5, the angle through which the rocking arm 4! must move in order to raise and lower the upper holding frame may be substantially reduced, thereby making it possible to produce an apparatus of minimum height when desired to do so. The chain block IE5} makes it possible to operate the frame moving mechanism with comparatively little effort, providing a suflicient mechanical advantage for that purpose.

Referring now to Fig. 14, I have there shown a simple means for operating the rocking arm M in cases where low cost of the apparatus is a determining factor. In this form of my invention, a rope or cable I2! is secured to the left end m4 of the rocking arm, the other end of the rope being adapted to be secured to the hook I05 arranged at the foot of one of the standards 22, after the lever has been manipulated as desired.

In Fig. 15, I have shown a modified form of the means for slidably supporting the counter weight 56 of Figs. 1, 2, l, 5 and 6. In this form of my invention, the bracket I28 for supporting the wheel 63 is offset in such a manner that the counter weight may pass to the extreme end of the rocking arm 4|. The stop I29 is made at said extreme end and replaces the stop 58 of Fig. 2. The cable 62 is secured to the counter weight near its front end as at I30 to shorten the over-all length of the rocking arm. In Fig. 15, I have further shown means for reducing the resistance to the movement of the counter weight 56 along the arm iI. Said means takes the form of suitable rollers I3! revolubly mounted on pins I32 on the counter weight and rolling on tracks I I3, preferably made integral with the rocking arm.

It will be understood that the flexible connections between the rocking arm and the frame slides may be considerably varied to conform to various types of printing frames and photo composing machines or the like. Further, if desired, the weight of the holding frame and of the parts connected thereto may be counterbalanced by a counter weight arranged in any desired position to reduce the power required to swing the lever.

It will be seen that I have provided means for operating the holding frames of printing apparatus rapidly and at low cost, for interchanging the frames, for insuring against undesirable movement of the blanket thereof, and adapted to meet the severe requirements of practical use.

While I have shown and described certain speciiic embodiments of my invention, I do not wish to be understood as limiting myself thereto, but intend to claim my invention as broadly as may be permitted by the state of the prior art and the scope of the appended claims.

I claim:

I. In a photographic printing apparatus, a pair of separable holding frames, a lever pivoted on a horizontal axis in spaced relation to the frames, and means operatively connecting the lever to one of the frames for raising and lowering said frame on the swinging of the lever, said means transmitting the weight of said frame to one end of the lever.

2. In a photographic printing apparatus, a pair of separable holding frames, a pivotally mounted lever, and means for separating said frames on the swinging of the lever in a given direction including flexible connections between said lever and one of the frames, said connections being tensioned on the swinging of the lever in one direction to transmit the weight of said frame to the lever, and said connections being slackened on the swinging of the lever in the other direction to permit said frame to drop by gravity.

3. In a photographic printing apparatus, a pair of separable holding frames, a lever, mean-s operatively connected to the lever for raising and lowering one of said frames on the operation of said lever, and cushioning means arranged in the path of said lever to resist the last part of the movement of said lever and to support the lever.

4. In a photographic printing apparatus in-- cluding a frame, a swingable lever carrying the weight of said frame, and means including a movable weight operatively connected to the lever for swinging the lever to raise and lower said frame.

5. In a photographic printing apparatus including a frame, a swingable lever carrying the weight of said frame, means operatively connected to the lever for swinging the lever to raise and lower said frame, and air cushioning means arranged in the path of said lever. 6. In a photographic printing apparatus including a frame, a lever operatively connected to the frame, a weight movable relatively to the frame, and means for manipulating the weight for swinging the lever.

7. In a photographic printing apparatus including a frame, means for moving said frame comprising a lever, and a movable operating weight for the lever.

8. In a photographic printing! apparatus, a frame, means for slidably supporting the frame for vertical movement, a lever supporting the weight of the frame, a flexible member connecting the frame to one end of the lever, and means including a second flexible member at the other end of the lever for swinging the lever and thereby adjusting the vertical position of the frame.

9. In a photographic printing apparatus, a pair of holding frames, means retractable below the lowermost frame for supporting the uppermost frame, means on the frames for selectively engaging the retractable means, a fixed pivot;

means for operatively connecting the pivot to the lowermost frame and also to the uppermost frame when the uppermost frame rests on the lowermost frame, and lever means for raising and lowering the uppermost frame when the pivot connecting means is disconnected therefrom. V

10. In a photographic printing apparatus, a pair of holding frames, means for pivotally supporting one of said frames, means for slidably supporting the other frame for movement toward and from said one frame, and means for removably holding said frames together for pivotal movement as a unit about said pivotal supporting means whereby the relative positions of said frames may be reversed, said pivotal supporting means comprising a plate of a height substantially equal to the combined; heights of said frames, a pivot pin projecting from the plate and removable fastening means passing through the plate and adapted to enter the frames.

11. In a photographic printing apparatus provided with a pair of cooperating holding frames, an upright slide support at each end of the frames, a slide on each support, means on the slides for supporting the uppermost one of the frames only, said means being retractable out of engagement with the uppermost frame when said uppermost frame rests on the lower'frarne, and means operatively connected to the slides for raising and lowering said slides and thereby correspondingly moving one of the. frames.

12. In a photographic printing apparatus provided with a pair of cooperating frames, an upright slide support at each end of the frames, a slide on each support, and a frame supporting member on each of the slides adapted to engage and support the uppermost of the frames only, said member being retractable out of engagement with the uppermost frame when said uppermost frame rests on the lower frame.

13. In a photographic printing apparatus provided with a pair of cooperating frames, an upright slide support at each end of the frames, a slide on each support, a frame supporting member on each slide movable below the lowermost of the frames, and means on the frames for selectively engaging the frame supporting member to support one of the frames only when said one frame is in a position above the other frame.

14. In a photographic printing apparatus provided with a pair of cooperating frames, means for pivotally supporting one of the frames, and movable means, disconnectable from and retractable below both of said frames, for normally sup porting the other of the frames for vertical movement therewith.

15. In a photographic printing apparatus, a holding frame, means for slidably supporting the frame for vertical movement, and means for moving said frame including a pivoted lever, a flexible member operatively connected at one end to the frame, and at its other end to the lever, and a revoluble wheel interposed between the lever and the frame and engaging the member and changing the direction of movement thereof.

16. In a photographic printing apparatus, a holding frame, means for slidably supporting the frame for vertical movement, and movable means for normally sustaining the weight of the frame and for determining the vertical position thereof in the apparatus, said movable means comprising a lever extending across the apparatus, and flexible means connecting an end of the lever to the supporting means whereby move ment of the lever in a direction to slacken the flexible means releases the frame to drop by gravity.

17. In a photographic printing apparatus, a holding frame, means for supporting the frame for vertical movement comprising a pair of spaced uprights, a slide on each of the uprights, a supporting member adjustably carried by each of the slides, projecting pins on th frame adapted normally to be engaged by the supporting member to support the frame when the frame is otherwise unsupported and to be disengaged from the supporting member when the frame is otherwise supported, a lever arranged above the frame and pivoted intermediate its ends, flexible members connecting the lever and the slides, and means including a flexible member held by the lever for swinging said lever in a given direction to raise the frame and to swing the lever in the opposite direction to slacken said flexible connecting member and thereby to permit the slides and the frame to drop by gravity.

18. In a photographic printing apparatus, a pair of frames, a support adapted to engage and support the uppermost of the frames only, said support being retractable out of engagement with the uppermost frame when said uppermost frame rests on the lowermost frame, means on the frames for selectively engaging the support to support one of the frames only, a pivot, and means removably securable to both of said frames for supporting the pivot centrally of both of said frames when the uppermost frame rests on the lowermost frame.

HARRY C. JONES. 

